How it is calculated
Alcohol, fibre, and organic acids are not part of that trio. The Atwater numbers are rounded.
kcal = protein × 4 + fat × 9 + carbs × 4
Where the numbers come from
- Protein — unit in the field: g
- Fat — unit in the field: g
- Carbs — unit in the field: g
Example
10 g each of protein, fat, and carbohydrate give 40 + 90 + 40 = 170 kcal.
Questions
Is fiber also × 4?
If it is already inside the carbohydrates on the label, do not add it a second time.
Per 100 g or per serving?
For the grams you entered.
Why does fat count for more?
A gram of fat holds more energy than a gram of protein or carbohydrate.